Phelps, C. | Search bioRxiv

bioRxiv2025

Does field margin semi-natural habitat amplify theabundance of beneficial spiders in a vineyard canopy?

I compared spider counts from a transect bordered by a semi-natural habitat to those of a control transect in a California Central Coast organic vineyard over the course of the 2018 growing season, observing spiders in blue vane traps that had been suspended in the canopy fruit zone. Ranked abundance analysis of spider counts did not confirm a difference between the two transect populations for any time period and a population gradient proceeding from the vineyard edge into the vineyard center was not identified for either transect. I suggest that semi-natural habitat proximity does not promote spider populations in the ecological context of a classical Central Coast vineyard.

ecology↗

bioRxiv2019

High-throughput single-particle tracking reveals nested membrane nanodomain organization that dictates Ras diffusion and trafficking

Membrane nanodomains have been implicated in Ras signaling, but what these domains are and how they interact with Ras remain obscure. Using high throughput single particle tracking with photoactivated localization microscopy and detailed trajectory analysis, here we show that distinct membrane domains dictate KRas diffusion and trafficking in U2OS cells. KRas exhibits an immobile state in domains [~]70 nm in size, each embedded in a larger domain ([~]200 nm) that confers intermediate mobility, while the rest of the membrane supports fast diffusion. Moreover, KRas is continuously removed from the membrane via the immobile state and replenished to the fast state, likely coupled to internalization and recycling. Importantly, both the diffusion and trafficking properties of KRas remain invariant over a broad range of protein expression levels. Our results reveal how membrane organization dictates KRas diffusion and trafficking and offer insight into how Ras signaling may be regulated through spatial mechanisms.

biophysics↗